1. Field of Invention
The present invention relates, in general, to a hybrid power train for vehicles, and more particularly, to a structure of a power train for hybrid vehicles, using a double clutch transmission (DCT).
2. Description of Related Art
In order to cope with the increase in oil prices and the regulations concerning CO2 in the environment that have recently increased, there is an actual need to further improve the fuel efficiency of vehicles. At the present time, improving the efficiency of a drive system which plays a part in the power transmission and improving the efficiency of an internal engine may be the most practical way to deal with such a need.
The most efficient transmission in conventional driving systems is a manual transmission. Since the transmission efficiency of a double clutch transmission (DCT) designed based on this manual transmission is superior to that of an automatic transmission (AT) or a continuously variable transmission (CVT), if a hybrid type transmission in which such an efficient DCT and an electric motor are combined together is designed, the fuel efficiency of the currently available internal engines can be further improved.
However, a conventional hybrid power train has a structure in which as shown in FIG. 1, an electric motor 504 is inserted between an engine 500 and a transmission 502, so that the length of the transmission shown in FIG. 1 becomes longer than that of the conventional AT or CVT since the structure of a conventional DCT generally is such that two clutches are disposed in an overlapped fashion in an axial direction. Such a structure makes much the entire length of a mounting space for the engine 500 and transmission longer, thereby reducing its ability to be mounted in a vehicle.
The information disclosed in this Background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.